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From Wiktionary under the GNU Free Documentation License. X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3 × 10 Hz to 3 × 10 Hz) and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma rays. In many languages, X-radiation is called Röntgen radiation, after Wilhelm Conrad Röntgen, who is generally credited as their discoverer, and who had named them X-rays to signify an unknown type of radiation. X-rays from about 0.12 to 12 keV (10 to 0.10 nm wavelength) are classified as "soft" X-rays, and from about 12 to 120 keV (0.01 to 0.10 nm wavelength) as "hard" X-rays, due to their penetrating abilities. Hard X-rays can penetrate solid objects, and their largest use is to take images of the inside of objects in diagnostic radiography and crystallography. As a result, the term X-ray is metonymically used to refer to a radiographic image produced using this method, in addition to the method itself. By contrast, soft X-rays can hardly be said to penetrate matter at all; for instance, the attenuation length of 600 eV (~ 2 nm) x-rays in water is less than 1 micrometer. X-rays are a form of ionizing radiation, and exposure to them can be a health hazard. The distinction between X-rays and gamma rays has changed in recent decades. Originally, the electromagnetic radiation emitted by X-ray tubes had a longer wavelength than the radiation emitted by radioactive nuclei (gamma rays). Older literature distinguished between X- and gamma radiation on the basis of wavelength, with radiation shorter than some arbitrary wavelength, such as 10 m, defined as gamma rays. However, as shorter wavelength continuous spectrum "X-ray" sources such as linear accelerators and longer wavelength "gamma ray" emitters were discovered, the wavelength bands largely overlapped. The two types of radiation are now usually distinguished by their origin: X-rays are emitted by electrons outside the nucleus, while gamma rays are emitted by the nucleus. From Wikipedia under the
GNU Free Documentation License What is the shortest wavelength present in the radiation from an x-ray machine? Q. What is the shortest wavelength present in the radiation from an x-ray machine whose operating potential difference is 50,000 V? I've had the numbers and equations explained but it is totally over my head. Asked by You - Sun Mar 1 17:03:09 2009 - - 1 Answers - 0 Comments A. The speed of the electron striking the anode is a function of tube voltage. As the voltage (V) varies, so will the energy of the electron as it strikes the anode. This contributes to the white or continuous spectrum of X-ray wavelengths emitted from an X-ray tube. The shortest wavelength emitted is a function of the maximum voltage applied to the tube, and is given by the Duane-Hunt Law which states that the wavelength of greatest intensity is approximately twice that of the shortest wavelength (SWL) emitted . The minimum wavelength generated is given by the equation below: SWL = 1243/Vtube (SWL in nanometers) Gives at 50'000V a Shortest Wavelength of 0.02486nm Answered by amilo - Tue Mar 3 18:35:10 2009 What is the minimum potential difference that must be applied to an X-ray tube to knock a K-shell electron com? Q. What is the minimum potential difference that must be applied to an X-ray tube to knock a K-shell electron completely out of an atom with Z = 29? Use the Bohr model as needed. Asked by Nessa - Sun Apr 12 05:38:27 2009 - - 1 Answers - 0 Comments A. E=Z^2*E0*(1/nf -1/ni) here nf =infinity so 1/nf=0 , ni=1 the energy is positive E0 =13.6eVso 13.6*1.6*10^-19J=2.178*10 ^-18J as z=29Z^2=841 and E=2.178*10^-19*841=1.83*1 0^-15J Answered by maussy - Thu Apr 16 04:06:07 2009 How does dentist know how much to drill without an x-ray?
Q. My son just came back from the dentist with a big silver filling in a permanent molar. The strange thing was that no x-ray was taken. The dentist just felt around with pick and then did a lot of drilling. Was the cavity really as big as it looks. Or did dentist drill extra to guarantee he got the whole cavity? Asked by John - Fri Apr 2 17:33:07 2010 - - 3 Answers - 0 Comments A. An x-ray gives the dentist an idea how deep a cavity is; it will not tell him how much to drill. Doing a cavity depends a lot on tactile sense or feel. A cavity has a certain feel to it and healthy tooth structure has a distinct feel. That is the reason a dentist takes his explorer (aka "pick") to scrap the bottom of the tooth to see if all the decay has been removed. Color is not a good guide to use because healthy tooth material can also look dark or black. Answered by tooth975 - Fri Apr 2 19:28:25 2010 From Yahoo Answer Search: "X-ray" I Guess You Can Throw Yourself Into The Airport X-Ray Instead Of Walking ... - Gizmodo Australia
Sun, 29 Aug 2010 22:20:21 GMT+00:00 Instead Of Walking ... Gizmodo Australia Why jumping onto the conveyor belt for an x-ray would cross anyone's mind is beyond me. ... Liar, liar, pants on fire Feds keep x-ray images - Atlanta Journal Constitution (blog)
Wed, 11 Aug 2010 10:02:06 GMT+00:00 images Atlanta Journal Constitution (blog) Ever since the federal government began deploying the new-fangled, full-body x-ray machines at airports and federal buildings to make us safer, Uncle Sam ... Feds Now Admits to Storing Naked Body Images From Full Body X-Ray Scanners Lew Rockwell Government Airport Security Agency Caught Lying about New Scanners TMC Net Republicans request review of airport scanner safety SecurityInfoWatch HealthKey: Hospital lawyers fight claims of unnecessary stents - Baltimore Sun
Sun, 29 Aug 2010 21:37:04 GMT+00:00 Baltimore Sun After complaints about Midei were lodged by a patient early last year, reviewers for the hospital looked at X-ray images from the medical files of his stent ... From Google News Search: "X-ray" x ray 5 jpg
469px x 800px | 378.00kB [source page] Solving Structures of Small Molecules Sidst opdateret af From Yahoo Image Search: "X-ray" Airport ' X - ray art' courts TSA trouble | NetworkWorld.com Community
Paul McNamara Wed, 01 Oct 2008 23:23:56 GM I sent him the link about Roth's . X. -. ray. art and asked whether he thought this would a) work as the artist intends, and b) go over very well at your typical airport security station. His reply: It is beyond me why anyone would do anything ... From Google Blog Search: "X-ray" |





